Analysis of morphological variations among four wild populations of Portunus trituberculatus

Portunus triuberbuculatus is an important economical species in China.In recent years,the wild stocks of P.triuberbuculatus along the coast of China have suffered fatal decrease in their resources due to overfishing and cultivation.So it is very important to analyze the morphological diversity of P.triuberbuculatus. In October 2005,50 individuals were collected individually from four wild geographic populations distributed in the Yalu River estuary,Laizhou Bay,Zhoushan,and Haizhou Bay.In this research,cluster analysis,discriminant analysis and One-Way ANOVA analysis were applied in the analytical process.Based on 14 morphological characters of each population of P.trituberculatus from four locations,cluster analysis and discriminant analysis were conducted.Crabs from Haizhou Bay and Zhoushan were pooled into one group while crabs from Yalu River estuary and Laizhou Bay were pooled into another group by cluster analysis.In discriminant analysis,total accuracy rate of discriminant on female crabs from four locations was 87.0%.The accuracy rate of Haizhou Bay population was the lowest(80.0%),while that of Laizhou Bay population was the highest(92%).Total accuracy rate of discriminant on male crabs from four locations was 80.8%.Haizhou Bay population was the lowest at 72.0%,while Yalu River estuary population was the highest at 96%.The discriminant functions of the populations from four locations were established,respectively.One-Way ANOVA was conducted on 16 proportional parameters.The results showed that some proportional parameters were significantly different among the four populations.In this study all results supported that there were some morphological differences among the four populations,but variations of all the morphological traits were not characterized subspecies.Some integrative analysis was needed to distinguish accurately all geographic populations.